This invention relates to a carton processing system and a carton processing method in which the contents of the articles contained in a carton, such as the name, model name, design statements or quantities of the articles, are printed as a printing pattern on the surface of the carton formed integrally with a lid. The articles contained in the carton may, for example, be tape cassette casings or disc cartridge casings. With the carton processing system for color printing a carton board box housing e.g. tape cassette casings, a printing pattern, such as characters or picture patterns, is printed on a cardboard, such as crude roll paper or sheet. The printed crude roll paper or sheet is punched by a die matrix and cut to a pre-set shape. In addition, fold lines are applied at pre-set positions by press-working for folding to a carton shape.
The cardboard piece thus punched to a pre-set outer shape (punched carton unit) is folded along the folding lines and a sizing is applied to part of the folded surface. The punched carton unit is then assembled to the shape of a box. This box, that is the crude roll board or cardboard formed into a box shape, is referred to herein as a carton-shaped box product.
The conventional carton processing system is hereinafter explained. The carton processing system is roughly made up of a printing device for printing the crude cardboard, an assembly device for assembling the punched carton unit to a carton shape and a loading device for charging the articles in the carton-shaped box product.
The printing device prints a printing pattern at a pre-set position on the crude cardboard. The assembly device assembles the punched carton unit, obtained after punching the crude cardboard having the printed pattern printed thereon, to the shape of a carton-shaped box product. The loading device charges a pre-set number of the articles in the carton-shaped box product.
For printing the crude cardboard by the above-described carton processing system, the printing process performs a preliminary printing step for printing the printing pattern. This preliminary printing step is made up of first to sixth sub-steps as hereinafter explained with reference to FIG. 1.
The first sub-step is an original preparing sub-step of preparing a color printing original carrying a desired printing pattern, such as characters or picture pattern, desired to be printed in color on the crude roll paper or sheet. The second sub-step is a master making sub-step of preparing a color printing master plate for each of four colors for color printing on the crude roll paper or sheet. The third sub-step is a sub-step of adjusting and arranging each of the four-colored master printing plates.
The fourth sub-step is a position adjustment sub-step of adjusting the printing positions of the respective colors of the respective master plates and the overlapping state of the respective colors. With this position adjustment sub-step, the respective master plates are matched to the designated printing areas of the plain crude roll paper or sheet with respect to the X-axis position, Y-axis position and Z-axis position. The Y-axis position is the position on the Y-axis perpendicular to the X-axis, while the Z-axis position is the position in the direction of rotation about the Z-axis perpendicular to both the X and Y axes.
The fifth sub-step is a test printing sub-step for conforming the coloring positions of the respective colors. The sixth sub-step is the ink concocting sub-step of adjusting the color tone or viscosity of the printing ink. The crude roll paper or sheet is printed in the wake of the preliminary printing step consisting of these first to sixth sub-steps.
The deficiencies of the above-described carton processing system and the preliminary printing step used in the system are as follows: First, the carton processing system, which is in need of the six preliminary printing sub-steps prior to printing, is not suited to multi-species small-quantity production of cartons.
Second, with the carton processing system, the printed crude cardboard is punched and fold lines as well as cuts are formed therein. Since the carton processing system employs punching with the aid of a punching die matrix and press working, the punching position and cuts are susceptible to position errors. The result is that position errors are also produced in the printed pattern formed on the carton-shaped box product.
If, with the carton processing system, the printing device has a photosensitive drum, since the value of the bias voltage applied at the time of printing differs with the quality of the crude roll paper or sheet, such as high-quality Kent paper or regenerated paper, it becomes necessary to alter the value of the applied bias voltage depending on the quality of the crude roll paper or sheet.
In addition, since it is difficult in the adjustment operation performed in the position adjustment sub-step of the preliminary printing step to adjust the position of the printing pattern in the X-axis direction, in the Y-axis direction and in the rotating direction about the Z-axis into register with the designated printing area on the crude roll paper or crude roll sheet, it becomes necessary to effect position matching operations a plural number of times, with the consequence that prolonged time is consumed in the printing position adjustment operations. That is, the carton processing system is in need of large-sized device, including the printing device, and sufficient technical experience and skill for the operation and adjustment of the printing device.
On the other hand, with the conventional carton processing system, if the printing pattern for the article is changed, it becomes necessary to perform an operation of adjusting the printing position of the printing pattern even if the printing pattern has once been adjusted as to the printing position. That is, the position adjustment of the printing position of the printing pattern lacks in reproducibility.
For assuring reproducibility in the position adjustment of the printing pattern, the carton processing system may employ, as simplified means, a computer having a picture processing function. However, with the carton processing system, the output rate of the information signals, having the printing pattern position adjusted by the picture processing function, is slower than the production tact time on the carton processing line. The result is that the printing speed for the printing pattern by the printing device cannot be synchronized with the supply rate of supplying the article to the printing device. Consequently, this sort of the carton processing system has not been put to practical utilization.